The Digital Pre-Distortion (DPD) refers to performing pre-distortion processing on signals based on memory multinomial. After pre-distortion processing, a pre-distortion coefficient and an input signal are usually used together to determine a pre-distortion signal. For the training of the pre-distortion coefficient, a method in which a training sequence is stored in a base station and periodically sent is usually employed.
However, since the training sequence is not service data, periodically sending the training sequence may seriously interfere with users in the cell. For this reason, it is necessary to collect signals in real-time to train pre-distortion coefficients. However, the data collected in real-time cannot ensure an availability of the coefficient in this training. For example, the coefficient in this training is far away from that in last training.
If an inferior pre-distortion coefficient is adopted to perform the pre-distortion processing, the Adjacent Channel Power Ratio (ACPR) of the outputted signals after performing the pre-distortion processing may be deteriorated so as to seriously interfere with neighbor cells.